Engine exhaust silencer



Jan. 19, 1965 w. H. PHELPS 3,166,150

ENGINE EXHAUST SILENCER Filed Feb. 17. 1961 United States Patent 3,166,150 ENGHNE: EXHAUST. SELENCER Wiiliam H.-Pjheips,.427 Granada St, Los Angeles, aiif. Fiied Feb. 17, 1961, Ser. No. stasis .7 Claims. (Cl. 181-46) This inventionrelatesv tomeans for muffiing or silencing the exhaust of internal combustion engines and particularly to an improved form thereof characterized bya minimum of elements offering opposition to the free flow of the exhaust gases and the expansion thereof.

The principal object of this invention is to provide an exhaust silencing means for the engines of automotive vehicles characterized by means utilizing the impulses or surges of the exhaust from opposite groups or banks of cylinders of the engine to oppose'and cancel out each other with resultant primary diminution of the noise from theexhaust.

Another object of the invention isto provide a silencer for the exhaust of V-type vehicle engines in which half of the exhaust emissions of both banks of engine cylinders are directed into one expansion chamber and, the other half into another expansion chamber by conduit means of equal length and in which other, separate means are provided downstream of each of said expansion chambers for separately further absorbing the sound producing vibrations deriving from the remaining impulse traces in theseparate streams of exhaust gases.

With the above objects in view, together with such additional objects and advantages as maysubsequently appear, the invention resides in the parts, and in the construction, combination and arrangement of parts described, by way of example, in the following specification of a presently preferred embodiment of the invention, referencebeinghadtothe accompanying drawings which form a party of, said specification and in which drawings:

FIG..1 is a somewhat diagrammatic top plan view of a representative .vehicle. chassis and motor to which the invention is applied,

FIG. 2 is enlarged. side elevational View of the silencer unit;

FIGS. 3 and 4 are, respectively, front and rear elevational views of the silencer shown in FIG. 2,

FIG. -5 is atop-plan sectional view taken on the staggered line 5-5 of FIG. 2, and

FIG. 6 is a'transverse sectional view taken on the line 65 of FIG. 2.

Referring to FIG. 1 there is shown a plan view of a vehicle chassis including a motor M, a frame F, front wheels W and rear wheels W connected to the motor end through drive shaft'means D. The motor is of V- type having a left hand cylinder bank LC including an exhaust manifold LE having the front end thereof connected by an exhaust pipe 1 to a first inlet port thimble 2 of the silencer 3. The other cylinder bank RC includes an exhaust manifold RE having the rear end thereof connected by an exhaust pipe 4 to the second inlet port thimble 5 of the silencer 3.

The silencer 3 comprises an elongated, oval, sheet metal body 6 closed at its forward end by a wall 7 through which the inlet port thimbles 2 and 5 conduct the exhaust gases to the interior of the silencer. At its rear end the body 6 is closed by a wall 8 through which exhaust port thimbles 9 and 10 deliver the exhaust gases from the silencer.

The silencer is shown mounted below the vehicle frame in horizontal position parallel to the length of the vehicle and adjacent to the left hand side of the vehicle. It l$ '0f importance, as will be later explained, that the pipes 1 and 4 beef the same length, wherefor, as will 3,16%,i5h Fatented Jan. 19, 1965 be noted the pipe 1 which is on the same side of the vehicle as the silencer extends from the front end of its manifold while the pipe 4, due to the fact that it extends laterally across the vehicle, connects from the rear end of its manifold. The major axis of the oval cross section of the silencer body is disposed horizontally and a longitudinally extending verticalwall 11 bisects ,the interior of the silencer into chambers 12 and 13.

The inlet port thimbles 2 and-5 are disposed with the axial lines thereof coincident with the plane of said vertical wall as is best shown inFIGS. 3 and 6 and consequently one-half of the exhaust emissions of each bank of cylinders is diverted into the chamber 12 and the other half of the exhaust emissions is diverted into the chamber 13.

The outlet port thimbles 9 and 10 (see FIG. 4) are disposed at opposite sides of the wall 11 and the outlet port thimble 9 conducts all of the gases from the chamber 12into a pipe 114 leading to a glass fiber packed secondary mufiler 15 and a separate tail pipe 16 delivers the gases to atmosphere. Correspondingly, the exhaust port thiinble 1th conducts all of the gases from the chamber 13 into a pipe 17 leading to a corresponding secondary muilier 18 and a tail pipe 19 delivers the gases to atmosphere. By this arrangement, it will be noted that each tail pipe receives and discharges one-half of the total exhaust emission from both banks of engine cylinders.

Due to the identical length of pipe 1 and 4, the exhaust impulses of the various. cylinders of the left bank will reachthe silencer 3 in the same time intervals as the corresponding impulses from the right hand bank of cylinders. By way of example, as'an exhaust impulse from the left hand bank of cylinders enters the chambers 12 and 13 through the inlet port thimble 4 and then starts to expand in a downwardly and'rearwardly moving surge, it is rnet almost immediately by an equivalent rearwardly and upward-1y moving. surge froman exhaust impulse received from the right hand bank of cylinders entering the chambers 12 and 13 through the inlet port thimble 5 and that impulse or surge in turn is met and opposed by the next-following surge or impulse received from the left hand bank of cylinders. Since the frequencies are the same, these impulses tend to. cancel each other out and as the gases flow through the respective exhaust port thimbles they have analmost uniform velocity, wherefore, such flow is substantially noiseless. Any remaining pulsations in the exhaust are substantially eliminated by the individual, secondary glass fiber packed mufflers 15 and 18. Since there are no opposing bafiies or the like, there is practically no back pressure on the exhaust other than the frictional engagement with the various pipes and hence there is no loss of engine power by reason of exhaust back pressure. Furthermore, the device is much more economical to manufacture since the primary silencer is formed with only a center longitudinal partition.

While the above disclosure relates to a presently preferred form of the invention it will be appreciated that the position of the silencer body 3 in the chassis dictates to a great extent the nature of the connection of the exhaust pipes 1 and 4. If this mufiier would be located on the right hand side of the chassis, the arrangement of the exhaust manifolds would be reversed. On some vehicles it is possible that it would be located near the center of the vehicle, in which case, both exhaust pipes might well lead from the rear end of the respective exli aust manifolds. Further, while the inlet ports are shown as located in the vertical plane, it may be that for some installations it will be found more practical and advisable to position the silencer body rotated p cv nd ts i tq.,.. v

' 1 isapar toss dnsai z new 1 fs i bo s '1 t g duct ecnt g exhaustlfi eh of ere sin fcy d rs into-said batt eac s id l n t ports.

h n 'adia tq medow tream: d h e van 63' from the illustrated position with the wall 11 disposed horizontally with the inlet ports located laterally spaced from each other and the outlet ports disposed vertically.

Having these and other modifications in mind, it will be understood that the invention is not to be deemed 'to be limited to the precise form thereof disclosed by way of example andit will be understood that the inventionincludes as well all such changes "and modifications in the parts and in the construction, combination arrangement of parts as shall come within the purview jot the appended claims,

1 'I n'asilencer}for the exhaustof 1a V'-t ype internal co bastion engine',-, anelongated hollow metal body hav- 'ingapair of walls closing the opposite-ends thereof and -fur;ther; having partitionmeans dividing the interior there-, of i'ntd' two l-longitudiriallyextending, parallel, substane ia iidcn i shambcrs we qnd it means including an-inletfport forrnl'edin one of said end walls operative the n ire ex a t f m; a o engine d body, a second; conduit means includhaust gas 2 .v divs 'tinam sss o e a to fdi s the elivere dinto' other i 14' In; a s lencerffor; the exhaust gfor l typejinternal" combustion :engines ghavjing separate 1 exhaust manifolds 1. toreac'h'j bank- 'of c'yl'inders, -an elongated, hollow metal body] having: :wa'lls ..'closi'ng each ,gv end thfiICOfy a medial partition iextending: between said ,end walls, and dividing 1 the interior ofqsaid' bOdY-{illfO-JtWOI chambers, :a jpair :jof

fgtheexhaust gases dei der bank atf'the side of the vehicle chassis to which said. 1 silencer body is adjacentfa second exhaust pipe connecting the other. of said inletportsto therear end of the ca s; sf l if i ii t l ififidi i sep r staikpia s e 'hha n ia' 'sspa a emu fl Q QiS-i charging exhaustfgases;receivedfroin saidfdischarge ports iv inlet ports extending through one of said end walls and disposed with the axial lines thereof in the plane of said partition, a pair of exhaust pipes connecting one each of said exhaust manifolds with one each of said inlet ports whereby exhaust gases entering said body through each of said ports is delivered in's'ubstantially equal quantities into both of said chambers, and a pair ofexhaust ports in the other of said end walls and disposed one each at each side of said partition whereby each of said exhaust ports delivers all of the exhaust gases from one each of said chambers;

5. An exhaust silencer as v claimed in claim 4 in which said exhaust pipes are of e'qual'length.

6. In a silencer for the exhaust of /,-type vehicle engines having separate exhaust manifolds for each bank of cylinders, a hollow metal body of greater length than diameter disposed beneath the vehicle chassis adjacent one side thereof and having a front wallanda rear wall,

a partition extending between said walls anddividingthe interior of said body into two substantiallyidentical chamber s, a pair of inlet portsfor'med in and extendingthrough said front wall and disposed with the axial lines thereof disposed coincident with the plane of said partition, an

exhaust .pipe connecting one of said, inlet ports to the front end of the exhaustmanifold serving the engine cylinexhaus t manifoldfserv'ingthe other cylinder bank ofthe engine, and a'pair of discharge portsin' saidrearwall communicating only one each with each of saidjcharnr t 7.,

7.-A sile ncer' means asclaimedfinclaim 6 in which each of said discharge'po'rts is'fco'nnected to one each' of a pair oftailpipes}.

r References Cited in the file of this patent f UNITED STATES PATENTS 

1. IN A SILENCER FOR THE EXHAUST OF A V-TYPE INTERNAL COMBUSTION ENGINE, AN ELONGATED HOLLOW METAL BODY HAVING A PAIR OF WALL CLOSING THE OPPOSITE ENDS THEREOF AND FURTHER HAVING PARTITION MEANS DIVIDING THE INTERIOR THEREOF INTO TWO, LONGITUDINALLY EXTENDING, PARALLEL, SUBSTANTIALLY IDENTICAL CHAMBERS, A FIRST CONDUIT MEANS INCLUDING AN INLET PORT FORMED IN ONE OF SAID END WALLS OPERATIVE TO CONDUCT THE ENTIRE EXHAUST FROM ONE BANK OF ENGINE CYLINDERS INTO SAID BODY, A SECOND CONDUIT MEANS INCLUDING A PORT FORMED IN SAID ONE WALL OF SAID BODY OPERATIVE TO CONDUCT THE ENTIRE EXHAUST FROM THE OTHER BANK OF ENGINE CYLINDERS INTO SAID BODY; EACH OF SAID INLET PORTS HAVING ADJACENT TO THE DOWNSTREAM END THEREOF AN EXHAUST GAS FLOW DIVERTING MEANS OPERATIVE TO DIVERT THE EXHAUST GASES RECEIVED IN EACH OF SAID INLET PORTS INTO SAID CHAMBERS IN SUBSTANTIALLY EQUAL PROPORTIONS, A FIRST EXHAUST DISCHARGE PORT FORMED IN ANOTHER WALL OF SAID BODY EFFECTIVE TO DISCHARGE ALL OF THE EXHAUST GASES DELIVERED INTO ONE OF SAID CHAMBERS, AND A SECOND DISCHARGE PORT FORMED IN SAID OTHER WALL OF SAID BODY EFFECTIVE TO DISCHARGE ALL OF THE EXHAUST GASES DELIVERED INTO THE OTHER OF SAID CHAMBERS. 